- Provision of privacy
This is really the ‘net curtain’ solution, if it is needed at all. Some form of
translucent material which lets through the maximum amount of
daylight, but breaks up the internal image seen from the outside. This
is less important during the day when the light ouside exceeds that
within and there is no disadvantage in placing the diffusing material on
the inside of the window. In certain security situations special materials
have been developed which in addition to the provision of privacy,
capture the shards of glass which occur when a window is broken
Solar shading solutions can broadly be divided into the following three
types:
1 External shading
2 Internal shading
3 Alternative glazing(Note. The BRE pamphlet further lists as a solution the reduction in the
area of glazing, comparing this with the loss of daylight associated with
the use of some form of tinted ‘sun control’ glazing. On the basis that the
window areas have been calculated correctly in the first place, this must
reduce the daylight available, and for this reason has not been included.)
- External shading
The following methods are available: Overhangs and canopies, light
shelves, fixed and movable louvres, shutters, vertical fins, deep window
reveals, egg-crate baffles, and roller blinds.
When choosing a method of external shading, the most crucial decision
that must be taken is the long-term viability of the hardware involved,
associated with the climatic conditions which will be experienced on site;
there is also the architect’s preoccupation with the exterior appearance of
the building with which the former is associated.
Whilst it is best to control the heat gain before it enters the building by
external means, any method of external shading can be vulnerable, and
the cost and long-term viability of the method employed must be
established. Comparisons should be made with internal shading meth-
ods, to establish whether the gains in heat control are sufficient to
warrant what will initially be expensive, and possibly a long-term
maintenance problem.
The following list of shading types are some of the options available,
each having their own advantages and disadvantages; although the
visual appearance of each type may have more influence with tbe
architect as to how he sees the impact on the elevation of the building:
Overhangs and canopies
Continental shutters, and awnings
Light shelves
Fixed and movable louvres
Egg-crate louvres
External roller blinds
Brise soleil- Internal shading
It must be recognized that any form of shading within the building
envelope is bound to be less efficient as a control of heat gain than an
Windows 31